Manufacture of 2-nitrodiphenyl



Patented Nov. 13, 1934 MANUFACTURE OF Z-NITRODIPHENYL No Drawing. Application December 22, 1933, Serial No. 703,677. In Germany December 24,

2 Claims.

My present invention relates to an improved process for manufacturing Z-nitrodiphenyl.

The manufacture of mono-nitrodiphenyl, the parent material for making mono-aminodi phenyl, is described in various literature. In an article by L. R. Jenkins and others (Industrial Engineering Chemistry, vol. 22, page 31 /34=) there is a useful summary of this literature. The nitration is conducted with strong nitric acid, a mixture of glacial acetic acid and nitric acid or the so-called mixed acid. In all cases the reaction produces i-nitrodiphenyl in by far preponderating proportions and only a small proportion of Z-nitrodiphenyl. The statement of Fortinski (J. Russ, Phys. Ch. Ges, 44, 781-87) that he obtained from 180 grams of diphenyl 105 grams of i-nitrodiphenyl and 110 grams of Z-nitrodiphenyl by nitration with a mixture of glacial acetic acid and nitric acid, that is to say a yield of about 45 and 47 per cent. respectively, has been rejected by de Crauw (Rec. trav. chim. 50 (1931) page 753 and following).

It is the object of the present invention to conduct the mono-nitration of diphenyl in such a manner that, in contrast with past experience, there is a satisfactory production of 2-nitrodiphenyl, since it is this body which has technical interest as being the material from which 2- aminodiphenyl, the intermediate product of the manufacture of dyes, is made.

The object is achieved by nitrating with strong nitric acid the diphenyl dissolved in carbon tetrachloride.

For example, to a solution of 1000 parts by weight of diphenyl in 3000 parts of carbon tetrachloride there is run, while strongly stirring, 1600 parts of nitric acid of 1.45 specific gravity in the course of 2 hours, the temperature being kept,

rice

by cooling, at about 18 C. The mixture is then heated to boiling in a reflux apparatus for 20 hours.

After it has cooled, the carbon tetrachloride layer is separated from the acid, washed with water until neutral and filtered from a small quantity of 4.4-dinitrcdiphenyl.

The carphenyl.

In the vacuum (13 mm.) the 2-derivative distils at 178 and 179 C. and the -derivative between 190 and 200 C. The distillation residue contains essentially 2,4-dinitrodipheny1 of melting point 93 C.

A similar effect is obtained when using chloroform as a solvent in which the nitration of diphenyl is carried out with strong nitric acid. With the aid of this chlorinated hydrocarbon nitration occurs very smoothly, whereat only mononitro derivatives are formed and orthonitrodiphenyl likewise is obtained with a satisfactory yield.

What I claim is:

1. The process which comprises nitrating diphenyl with strong nitric acid in the presence of a solvent of the group consisting of carbon tetrachloride and chloroform.

2. The process which comprises nitrating diphenyl with strong nitric acid in the presence of carbontetrachloride.

HANS LANGE. 

